Teflon-lined Fuel lines?

[GS guy]

Who's running teflon lined fuel lines and what products did you use?

I have 95% of my fuel system - EFI, 2 filters, pump, supply and return lines - plumbed with AN6 Aeroquip, a combination of AQP stainless and socket-less hoses and fittings. A lot of 90, 45 and a couple of other odd-ball angle fittings in the mix. This system has yet to be operational, all in mock-up stages so far as the rest of my Deserter GS buggy build progresses.

A while back I was looking for some fuel hose to use for my custom tank venting system, and ran across the whole "witches brew" alcohol/pump fuel debate and how it deteriorates older formulation fuel hoses. I ended up getting some Gates Barricade hose for my vent system, and now I'm second-guessing my choice of main fuel delivery hoses. Current discussions on the 'net indicate using a teflon lined fuel hose to 100% eliminate hose degradation, and especially hose permeation and fuel smell as fuel seeps and evaporates directly through the hose. If I decide to replace - it'll be an expensive $$$ proposition.

Anyone running any of the teflon lined hose systems in your car? Issues? Likes/dislikes?

I did come across a new "less expensive" Earls Vapor Guard elastomer based hose, but this still seems like a hose that will need periodic replacement (OK, may every 5-10 years??) and has limited fittings available. Their Ultra-Pro hose/fittings is what I'm looking at for a permanent solution.

Comments?

Thanks,
Jeff

[dragvw2180]

I had problems with the hose getting hard when I used the ones with liners plus the aluminum fittings deteriorated from the alcohol. The lines I am using now are PTFE , solid teflon wrapped in stainless with stainless fittings . When I plumbed my new car it really was not more expensive .

[Chip Birks]

I use http://www.anfittingsdirect.com/?osCsid ... 5d8a761a5cfor my fuel and oil lines. I run e85. No problems so far.

[Ol'fogasaurus]

http://iqlearningsystems.com/ethanol/do ... bility.pdf

[Piledriver]

Think "hydraulics" not "bling aluminum AN fittings" with teflon core hose, and you will save ~75% on fittings with zero alcohol incompatibility.

You might consider buying or renting a crimper, I'd love to get a set of hydraulic hose die I could use with my hydraulic AC crimper. (not sure it makes enough pressure)

Also:
Consider brake line (either the coated steel or cupronickel corrosion proof kind) and only use the flexline where required.
Smileys Racing sells various lengths of -4 AN teflon/SS braid brake lines (Goodridge mfr/teflon core) in many lengths straight or 1 90 all for under $15 each.

I used a pair of the -4s for my remote resis on my shortened Bilstein 36mm front coil overs, and the -3AN for my front brakes.(small line for remote reservoirs, but the shocks only have 11mm shafts, and ~5ish" usable travel, so there isn't much flow)

[Chip Birks]

Doesn't anodizing have a pretty good effect on the durability of said aluminum fittings when introduced to alcohols? That was certainly my understanding...

[GS guy]

After more research, it looks like there are lots of options on manufacturers/suppliers of teflon lined hoses. Also, the Aeroquip hoses (I have) may have better compatibility with fuels than similar Earls products (rubber inner hoses), but will likely require replacement anyway in a couple of years after exposure to the fuel.
Unfortunately, every hose "type" requires its own type of end-fitting - so all the AN6 (hose and fittings) I have now won't be transferable to a new hose "system".

I was wanting to keep all my plumbing products from one manufacturer (Aeroquip). While they do offer a line of SS braided teflon hose (and it's not significantly more expensive than the rubber hose products), it appears to be a white teflon brake-hose type of line, with steel or stainless end fittings. From what I'm reading fuel systems need a conductive teflon material (carbon mixed in) to avoid any kind of static charge build-up. Several other manufacturers offer this type of hose specifically for fuel systems - so the choice comes down to picking a system and re-building all my fuel lines.

On the bright side (I guess), I think I'm going to switch to a lighter and less-abrasive cloth braided hose covering instead of the SS braid. I'm still liking the Ultra-Pro stuff from Earls. Looks like a fairly new product, so not much discussion (pros/cons) about it I can find, but hose and fitting costs are reasonable, about all end-fitting types available, made in USA, and it's Earls - so at least at the mid-upper end on the quality scale.
Jeff

[Ol'fogasaurus]

One more thing to consider if you were still going to use SS hose: If I remember my training with them correctly, they were designed to be used in fairly short lengths not long lengths as the strands of SS wire will work harden as they flex then fracture putting out pieces/burrs to get stabbed on and will wear other soft lines that come in contact with them. Also, they are so hard to squeeze that to check their internal condition by squeezing on them is pretty hard to do.

The idea of using hard line, neatly bent to shape then connected by a short hose... if needed using an AN, AND, NAS, etal or any of the other "standards" connectors that fall in under the generic term "AN" fittings. A much cleaner, more sanitory less bulky look if you ask me. Think of the parallel piping you see in some storage or work plants all tucked in together so cleanly.

Did you know that the color of the anodize has a meaning? In the military the blue fitting could be disconnected/worked on w/o permission by a "next higher authority". Red color you had to have permission to mess with it. I think I remember seeing one or two other colors also but I am not sure if they carry a message in the military.

[dragvw2180]

Er , the stainless covering is conductive . I only have one black cloth braided Push Loc line on my car , a return line from my turbo to the engine, it leaks , go figure . LOL

[risk]

Did you know that the color of the anodize has a meaning? In the military the blue fitting could be disconnected/worked on w/o permission by a "next higher authority". Red color you had to have permission to mess with it. I think I remember seeing one or two other colors also but I am not sure if they carry a message in the military.

That's pretty cool info, never knew the colors had a meaning.

I run Aeroquip AQP stainless hose and the blue/red aluminum fittings with stainless hard line in the tunnel. Been running E85 through it for almost five years now with no issues, no leaks.

If I had it to do over, I would have gone with the black cloth braided hose and black fittings.

[GS guy]

Thinking this over, I decided to just bite the bullet. Once I get fuel in my existing hose(s) they're toast if I decide to replace them later, while they "could" still be useful for future projects if I keep 'em unused (no real shelf life limits). Just ordered up a 10ft section of -6 UltraPro hose and bunch of fittings. They're bound to be easier to assemble that SS braided hose & fittings! Looks like larger ID bores too.

[risk]

They're bound to be easier to assemble that SS braided hose & fittings!

https://www.youtube.com/watch?v=Y0K0FoY ... e=youtu.be

Looks a little more complicated... but a nice finished product!

[GS guy]

Got the hose and fittings - thanks to quick ordering and shipping by Jegs.

Right off the bat, I like these fittings as the hose fitting ID is fairly large. Here's a comparison between the Earls UltraPro (black), Aeroquip Socketless and Aeroquip AQP hose end fittings. The socketless wins, with a 0.300"ID, UltraPro 2nd @ 0.273"ID, and the AQP a distant 3rd @ 0.230"ID. Think about that, AN6 hose size but the fitting ID is less than 1/4"! I'm guessing other hose brands are similarly sized.



I'm using a gravity fed external 044 pump and originally plumbed to use the -6 socketless hose due to the larger "actual" 3/8" hose ID and larger ID fittings, with high pressure side fitted with SS braided AQP hose/fittings. I figured the higher pressure would overcome any ID restrictions. Now everything will be UltraPro sized.

Hose assembly went exactly as the video risk linked - no problemo! I did use a rubber strip between pliers and olive to help tighten it onto the hose, just can't see galling and scratching it up with some ham-fisted pliers action!



Hose flexibility is better than the AQP or socketless, seems to have about 2/3 minimum bend radius of the other hoses but still has some stiffness (it's not too floppy or flimsy). I may have to re-check my hose lengths because of this, might need some slight tweaking on the lengths with this new flexibility.
Jeff

[GS guy]

This brings up a question: How do you pressure-check your made-up hoses?

Sure, easy enough to fit a plug at one end, and modified fitting at the other to connect with an air hose. But how do you "constrain" the hose if one end were to blow off? Check it from a distance with an air flow valve? If one of the fittings were to pop off at 100+psi, it's gonna hurt whatever it hits!

[Piledriver]

Hold onto the hose and aim the end away from you?
My AC recovery pump can make 800 PSI out of thin air, have used it for pressure testing before.
An 044 dead heads at 160+ PSI.

I would advise finding out what the working and burst pressure is of the hose/fittings you are using before going there.